1. Field of the Invention
The present invention relates to a tanker liner system to prevent spillage of liquids in the event the hull of a tanker is damaged in an accident and to prevent fire or explosion due to the escape of gases from the storage material.
2. Prior Art
Recently, oil spills from tankers have become a major problem. Tanker accidents not only result in loss of the cargo but damage to the marine environment. Both the size and the frequency of the spills have dramatized the need for solutions to the problem.
A recent proposal has been to install double hulls on all ships, with a space provided between the hulls. If the exterior hull is ruptured, the integrity of the cargo would be maintained. This proposal is expensive and cuts down on the amount of usable storage space. It has been estimated that the tanker cost would increase 15 to 30 per cent.
An additional problem not solved by double hull tankers is the possibility of hydrocarbon or toxic vapors escaping or being allowed to combust with oxygen to produce a fire.
Presently, empty crude tankers will have their storage compartments filled with inert gases to prevent a buildup of dangerous hydrocarbon gases from the residue of previous cargoes.
Vapor control systems at dock side are increasingly being required to handle the vapors which are retained in the cargo areas.
The present invention would introduce a liner system to decrease the likelihood of spillage during a tanker accident and reduce the probability of explosion or fire from escaping gases.
A cost effective solution would be provided to a major environmental issue by reducing tanker spills, by increasing safety in transporting volatile products and by eliminating discharge of hydrocarbon vapors into the atmosphere.
Applicant has conducted a search and is aware of the following patents:
______________________________________ U.S. Pat. No. Inventor ______________________________________ 3,664,904 Cook 4,239,416 Borca et al. 4,516,692 Croley 4,653,663 Holtsclaw 4,863,339 Krein 4,930,661 Voorhies 4,941,589 Chen ______________________________________
The Cook patent discloses a self-sealing structure adapted for use in a container as a fluid barrier. The structure comprises a sealant material adapted to swell in the presence of certain fluids and is interposed between inner and outer layers.
The Borca et al. patent discloses a device used to line a cavity in the earth such as a reservoir or tunnel. The lining is a flexible, fluid impervious sheet, such as rubberized fabric supported by a gridlike skeleton structure which when under tension presses the liner against the walls of the cavity.
The Croley patent discloses a disposable container assembly useful for containing and shipping liquids or semi-liquids in bulk. It comprises of fiber board container body secured to a pallet in the upright position. A bag is contained within the interior of the structure containing a dispensing spout locked in a dispensing position on one side of the container.
The Holtsclaw patent discloses a clamping assembly used to secure a flexible liner to a storage tank. The device comprises a filling pipe and a venting pipe passing through a mounting plate attached to the outside of a storage tank.
The Krein patent discloses a method for positioning a waterproof liner in a semi-truck trailer container. A negative pressure is allowed to form in the space between the bag and the inner walls of the container causing the sides of the liner to move toward the sides of the container.
The Voorhies patent discloses a disposable container formed of corrugated paper material containing a molded plastic inner tank positioned upright in the container.
The Chen patent discloses a device for lining the inner surface of a cargo container. The device includes a flexible bag which outlines the entire inner surface wall of the cargo container and magnetic elements holding the bag against the inner surface of the wall. The device is designed to prevent the flexible bag from collapsing within the cargo container.
Accordingly, it is a principal object and purpose of the present invention to provide a liner apparatus to reduce the potential of spills from tankers and to reduce the venting of hydrocarbons or other toxic vapors from a tanker cargo into the atmosphere.
It is a further object and purpose of the present invention to provide a liner apparatus to absorb the impact in the event of rupture of the hull of a tanker while retaining the liquid cargo.